The Proteomics Core Facility makes advanced mass spectrometry instruments, expertise, and methods for protein analysis available to the Case Comprehensive Cancer Center (Case CCC) community. The Core includes two laboratory sites, one on the CWRU campus and one the CCF campus, with a current total of 6,000 sq ft of laboratory space. The Core is directed by Dr. Mark Chance and has a staff of approximately 20 individuals including scientists specializing in mass spectrometry, protein chemistry, instrument engineering, and bioinformatics. A total of 8 mass spectrometry systems are housed in the laboratories, including electrospray and Maldi, and ion trap, ToF, QTof, and FTMS systems. The services that are offered to the Case CCC community are wide-ranging; from a drop-off service for protein identification, to collaborative services for the detection and characterization of post-translation modifications, quantitative proteomics, and protein structural analyses to open instrument access for trained users. Members have used mass spectrometry from the Core, to reveal that the reversible dimethylation on K140 by histone-modifying enzymes occurs only when it is part of a promoter-bound complex. Other members have utilized the Core to identify DNMT1-associated proteins including HAUSP from a series of pull down experiments. In particular, in-solution samples generated from pull down experiments were analyzed by tandem MS. The Core has provided services for Cancer Center members from 7 of the 8 Scientific Research Programs.